Closure cap and liner therefor



Jan. 19, 1937. a BVSMITH $068,389

CLOSURE CAP AND LINER THEREFOR Filed Sept. 21, 1951' .2 fi fl wig/2INVENTOR. I

A TTORNEY atentecl Jan. 19, 197

attests ones can which "area Application September 21, 1931, Serial No.SGMDQZ 6 Claims. (on. sis-4.3)

The present invention relates to the sealing art, and more particularlyto a sealed package and cap therefor. I

In sealing containers with closures, particularly screw closure caps, itis customary to form a seal on the rim of the container by means of adisc of paper, cardboard, felt, cork, or other suitable material. Whenthe cap is applied to the container, the disc is pressed against the rimof the container by the cover portion of the cap and forms an edge seal.Such caps are used quite extensively and maybe made of metal or'variousmolding compounds.

One of the difficulties encountered with such caps is the tendency forthe liners therein to fall out during shipment of the caps to the packeror during the sealing of the caps to the containers. It is customary toship caps with the liners in them and, in large factories, to place thecaps in hoppers, where they are fed individually and applied tocontainers. The agitation of the caps,

both during shipment and while in the hoppers, tends to dislodge theliners. If-the cap is applied to the container without a liner, there isno seal and the product may spoil or leak out of the con-- tainer,rendering the entire package unsalable and sometimes damaging adjoiningpackages.

After the cap has been applied to the container, the rim of thecontainer becomes embedded in the relatively pliable sealing materialand a certain amount of adhesion exists between the sealing material andthe container, irrespective of the product in the container. In manyinstances, the product is tacky, which increases the adherence of theliner to the rim of the container. The result is that, when the cap isrotated to open the package, the liner leaves the cap and remains on therim of the container, making it necessary to pry it off. The consumerordinarily throws the liner away rather than to continue to pry it offafter each removal of the cap. When the liner is thrown away, the cap isno longer adapted to form an effective seal and the product deterioratesrapidly, causing dissatisfaction on the part of the consumer.

Various attempts have been made to eliminate the diiiiculties notedabove, and to provide a liner which will remain in the cap in all cases.In some instances, manufacturers have gone to the extent of gluing theliners in the caps. This is objectionable, due to the fact that itintroduces an additional operation in the manufacture of the caps and,because heat is ordinarily desirable for drying the glue, whichdecreases the rate of production.

A serious dificulty in connection with caps molded of bakelite, durezand the like is breakage during application to containers. Molded screwcaps are applied by sealing machines and substantial .rotative effortisapplied to the cap to obtain a secure seal. Such rotative effort in ahorizontal plane resolves itself into an increased force in a verticaldirection by reason of the incline plane action of the screw thread.

' Hence, if the rotation of the cap is stopped by the vertical sealingpressure, excessive vertical strains result, which break a substantialpercentage of the caps. This is objectionable,

The present invention aims to eliminate or minimize the above dimcultiesby preventing breakage and'by providing a cap adapted to retain theliner during shipment and application,

and to remove the liner from the container when the cap is removedtherefrom. These advantages are achieved without the use of glue orother ad hesive materials.

An object of the present invention is to provide an inexpensive closurecap adapted to engage and retain a liner in proper position at alltimes.

Another object of the invention is to provide a closure cap adaptedautomatically to break or impair the adhesion between the liner and therim of the container, when the cap is rotated or removed. g

Another object of the invention is to prevent relative rotation betweenthe closure cap and liner therefor, without the use of adhesivematerial. a

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one embodiment of the presentinvention;

Fig. 2 is a sectional view of a closure-cap illustrating anotherembodiment of the invention;

Fig. 8 is a fragmentary bottom view of a closure cap illustrating adifferent embodiment of the liner holding means; 1

Fig. 4 is a sectional view of another embodiment of the invention;

Fig. 5 is a partial sectional view of a slightly different construction;

Fig. 6 is a top plan view of a preferred form of liner;

Fig. 7 is a fragmentary sectional view, on the line 'I'| of Fig. 4,illustrating the liner in Fig. 6 within a cap; and

Fig. 8 is a sectional view, similar to Fig. '7, illustrating a circularliner applied to the closure cap in Fig. 4.

Referring again to the drawing, and more particularly to Fig. 1, thereis shown a container 8, threaded at its upper end and having a screwclosure cap 2 sealed thereon. The closure cap may be made of anysuitable material, preferably of a molded composition such as phenoliccondensation products, the materials known under the trade names ofdurez, bakelite, and similar products, although many of the features ofthe invention may be utilized in caps made of metal. The cap comprisesthe usual cover portion d and depending skirt 5. A suitable thread 6 isformed on the inner Wall to co-operate with a corre-- sponding thread ion the container i. A suitable liner 3, which may be made of felt with asheet of oil paper on the lower surface thereof, is intermediate theunder side of the cover of the cap and the rim of the container. Whenthe cap is screwed on the container, this liner is com-=- pressedsuficiently to form a seal on the rim of the container and to preventthe contents from escaping. I

The capis provided wltha series of projections @,'shown extendingdownwardly from the lower surface of the cover of the cap in Fig. 1. Asillustrated, these projections are inclined slightly, to the left inFig. to assure rotation of the liner with. the cap when the cap isturned counterclockwise for removal. It will be understood, of course,that these projections may be substantially vertical, as illustrated inFig. 2. In any event, when the closure cap is screwed home, theseprojections bite into, or engage, the upper surface of the linermaterial without affecting the seal on the rim of the container. Whenthe cap is unscrewed, these projections forcibly rotate the liner withthe cap, thereby breaking any adhesive contact which may exist betweenthe rim of the container and the liner. In this way, the forces tendingto hold the liner on the rim of the container are eliminated, so thatthe liner will come off the bottle with the cap, substantially theentire tendency for the liner to drop out or remain on the containerbeing measured by the weight of the liner. As shown in Fig. 1, the

, projections 9* are inclined slightly to the left so that theyeffectively engage the liner on backward rotation of the cap. y

In this manner, the liner, while not glued to the cover part of the cap,is nevertheless forcibly removed from the rim of the container when thecap is turned backward, so that it will come off the container andremain'in the cap. During the application of the caps, the projectionscause the liner to rotate with the cap as soon as the sealing pressurebecomes sufllcient to imbed the projections in the liner. The rotationof the liner as the cap is screwed home increases the frictionalresistance to rotation as soon as an effective seal has been obtained.and thereby minimizes breakage of the caps.

In Fig. 2, the downwardly extending projections in the cover portion ofthe cap are shown manner.

made with a mold having a solid pin for the into be substantiallyvertical. A series of horizontal ribs ill, in the skirt of the cap, areadapted to engage the periphery of e liner to provide a lifting forcetending to prevent the liners from dropping out of the caps and tending,also, to pull the liners from the'rims of the containers. The horizontalprojections l0 co-operate with'the vertical projections 9 to preventrelative rotation between the liner and the cap and to raise the linerfrom the container when the cap is removed.

Fig. 3 illustrates a different form of projection in the cover of thecap adapted to pierce the upper surface of the liner. These projectionsQ l2 are sharp, but of substantial length, extending in a radialdirection of the cap. They operate in substantially the same manner asthe projections 9, illustrated and described with respect to Figs. 1 and2.

In Fig. 4, a liner recess [4 is provided, by means of the horizontalribs i5, to receive the periphery of the liner and retain it inposition. The liner recess has a series of vertical projections 15adapted to engage the periphery of the liner to hold it againstrotation. The ribs 45 serve the purpose of the ribs it, in Fig. 2, whilethe projections it tend to prevent the rotation of the liner withrespect to the cap.

The closure cap shown in Fig. 5 is similar to v that shown in Fig. i,except that the projections iii are substantially conical, for engagingand supporting the periphery of the liner.

It will be understood that any type of liner may be used in the presentcap. A preferred embodimer t of the liner, however, is shown in Fig. 6,with an irregular outer contour E8, in the form of saw teeth, adapted toengage the inner side wall of the skirt of the cap. Such a liner isparticularly applicable to a construction such as that shown in Figs. 4and 5, where the saw teeth engage the projections i6 and H to preventrotation of the liner. This is illustrated more particularly in Fig. '7.A circular liner may be eiiectiveiy used, as illustrated in Fig. 8. Theprojections IE or H, as the case may be, will engage and formindentations in the periphery of the liner and hold it securely againstrotation.

The closure cap illustrated herein may be made by a collapsible mold, orin any other desired Preferably, however, the closure is terior thereof,and the cap is stripped from the pin. The most convenient way ofstripping the cap is to remove the cap and pin from the outer mold andthereafter engage the cap to pull it from the inner mold or pin. It hasbeen found that materials such as phenolic condensation products areslightly elastic, particularly in their heated state, and the solid pinforming the interior of the cap may be removed by a stripping action, asdistinguished from the usual unscrewing operation. The present caps canalso be made in the usual type of mold, where the solid pins areunscrewed from the interior of the cap in the same way that they havebeen made heretofore.

In this instance, however, the-projections, such as the projections i0and II, will be stripped in the unscrewing operation. The resilience ofthe cap, while in a semi-plastic condition, will prevent theseprojections from being broken.

In applying the caps to the containers, the projections in the coverportion of the cap will be forced down into the upper surface of theliner to force the liner to rotate with the cap and to prevent itsrotation with respect to the cap. The friction between the rotatingliner and hit tilt

the rim of the container provides a force counteracting the rotativeeffort utilized in applying the cap, thereby preventing excessivestrains in a vertical direction by reason of the thread leverage on theskirt of the cap and minimizing breakage of molded caps. When the cap isunscrewed, the liner will be rotated with the cap and any adhesionbetween the liner and the rim of the container will be broken, so thatthe liner may be removed readily. The projections on the inside of theskirt of the cap co-operate with the periphery of the liner to effectthe same result. In addition, the liner retaining ledges forming therecess in the upper part of the cap, to support the liner duringshipment of the cap and during application thereof, co-operate with theprojections to pull the liner off the rim of the container.

It will be seen that the present invention not only prevents the linersfrom falling out of the caps during shipment and application of the capsto the containers, but also prevents relative rotation between the linerand the cap. In the application or such a cap, the frictional resistancebetween the bottom of the liner and the rim of the container makes thecap harder to rotate, thereby preventing the cap from being screwed ontoo tight by sealing machines. This minimizes the vertical strains onthe cap and the breakage of molded caps resulting therefrom. Backwardrotation of the cap forcibly breaks any adhesion between the liner andthe container in the removal operation, thereby permitting the liner tobe readily removed from the container. Unsealed packages are eliminatedand deterioration of the contents of opened package s is minirnized, dueto the fact that secure seals may be repeatedly made by the consumer.The cost of the cap is not materially increased because it may be madein substantially the same manner that the present types of molded capsare made. The production of the caps on existing machines simplifies thecommercial introduction thereof and minimizes the expense in connectiontherewith.

As various changes may be made in the form, construction and arrangementof the parts herein without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in a limiting sense.

Having thus described my invention, I claim:

1. A molded closure cap having a cover portion and a depending skirt,and a series of sharp projections on the cover portion of the cap spacedfrom the skirt of the cap adapted to engage and pierce the upper surfaceof a disc liner when the cap is screwed on a container to make the capand liner rotate together and thereby increase the resistance to turningand minimize the strains on the cap.

2. A molded closure cap comprising a cover portion, a depending skirt, aliner, liner engaging means integral with the upper portion of saidskirt adapted to hold the liner within the cap, and downwardly extendingmeans on the under side of the cover portion above the rim of thecontainer adapted to indent the upper surface of said liner when the capis screwed on a container to hold said liner so that it willsubsequently rotate with the cap.

3. A closure cap molded of a phenolic condensation product or the like,comprising a cover portion, a depending skirt, a sealing disc in saidcap adjacent to the cover portion thereof, and a plurality ofprojections molded independently of the contour on the exterior of thecap and being integral with and extending downwardly from the under sideof the cover portion of the cap, said projections being adapted to bepressed firmly against the sealing disc when the cap is applied to acontainer, thereafter to resist rotation of said sealing disc withrespect tothe cap.

l. A molded closure cap comprising a cover portion, a depending skirt, adisc liner, and a series of tooth-like projections molded on andextending downwardly from the cover portion of said cap, saidprojections being adapted to indent the upper surface of said liner andbeing inclined to the vertical so that they will exert greater rotativeeffort on said liner when the cap is unscrewed from a container thanwhen it is screwed on a container.

5. A screw closure cap molded of ;a frangible material comprising acover portion, a depending skirt, a sealing disc in said cap adjacentthe cover part thereof, said sealing disc being sufflciently largenormally to remain in the cap, and elongated radially extending ridgesmolded on the under side of the cover portion of said cap above the rimof the container adapted to engage and indent the upper surface of saidsealing disc and press the sealing disc against the rim of thecontainer, whereby said ridges forcefully engage the disc and preventrotation of the sealing disc thereafter with respect to the cap duringapplication and removal thereof.

6. A screw closure cap molded of a synthetic resin or the like,comprising a cover portion, a depending skirt, screw means for attachingthe cap to a container, a liner in the cap, means molded on the interiorof the skirt for engaging and supporting the liner in the cap, the underside of the cover portion of said cap having ridges located in the coverportion oi the cap above the rim of the container to which it is to besealed

